Allozyme electrophoresis was used to determine the systematic affinities of nine forms of carrion-breeding blowfly of the genus Calliphora: C. stygia, C. albifrontalis, C. augur, C. dubia, C. hilli hilli, C. hilli fallax, C. varifrons, C. sp. nov., and C. maritima. The results (1) confirm the species status of all forms currently described as such, (2) support a return to the ranking of C. hilli fallax as a full species, C. fallax, (3) support the recognition of C. sp. nov. as a distinct species, and (4) indicate that distinct Kangaroo Island and adjacent mainland subpopulations appear to exist in at least three species. The allozyme data also strongly support the placing of eight of the forms into three separate species-groups on morphological grounds, and the placement of C. maritima in a fourth group. However, on the basis of these data, the comparative genetic affinities of the parasitic blowfly Onesia tibialis suggest that Calliphora in its current form may be paraphyletic.